Vigano L.,National Research Council Italy |
De Flora S.,University of Genoa |
Gobbi M.,Laboratory of Pharmacodynamics and Pharmacokinetics |
Guiso G.,Laboratory of Pharmacodynamics and Pharmacokinetics |
And 5 more authors.
Aquatic Toxicology | Year: 2015
Juveniles (50 days post hatch) of a native cyprinid fish (Barbus plebejus) were exposed for 7 months to sediments from the River Lambro, a polluted tributary impairing the quality of the River Po for tens of kilometers from their confluence. Sediments were collected upstream of the city of Milan and downstream at the closure of the drainage basin of the River Lambro. Chemical analyses revealed the presence of a complex mixture of bioavailable endocrine-active chemicals, with higher exposure levels in the downstream section of the tributary. Mainly characterized by brominated flame retardants, alkylphenols, polychlorinated biphenyls, and minor co-occurring personal care products and natural hormones, the sediment contamination induced reproductive disorders, as well as other forms of endocrine disruption and toxicity. In particular, exposed male barbel exhibited higher biliary PAH-like metabolites, overexpression of the cyp1a gene, vitellogenin production in all specimens, the presence of oocytes (up to 22% intersex), degenerative alterations in their testis, liver fat vacuolization, a marked depression of total thyroxine (T4) and triiodothyronine (T3) plasma levels, and genotoxic damages determined as hepatic DNA adducts. These results clearly demonstrate that Lambro sediments alone are responsible for recognizable changes in the structure and function of the reproductive and, in general, the endocrine system of a native fish species. In the real environment, exposure to waterborne and food-web sources of chemicals are responsible for additional toxic loads, and the present findings thus provide evidence for a causal role of this tributary in the severe decline observed in barbel in recent decades and raise concern that the fish community of the River Po is exposed to endocrine-mediated health effects along tens of kilometres of its course. © 2015 Elsevier B.V. Source
New insights into the molecular mechanisms underlying sensitivity/ resistance to the atypical retinoid ST1926 in acute myeloid leukaemia cells: The role of histone H2A.Z, cAMP-dependent protein kinase A and the proteasome
Fratelli M.,Laboratory of Molecular Biology |
Fisher J.N.,Laboratory of Molecular Biology |
Paroni G.,Laboratory of Molecular Biology |
Di Francesco A.M.,Catholic University of Rome |
And 11 more authors.
European Journal of Cancer | Year: 2013
ST1926 is an atypical retinoid and a promising anti-tumour agent with selective apoptotic activity on the leukaemic blast. The anti-tumour activity of the compound has been associated with its capacity to induce DNA double stranded breaks. Target profiling by affinity chromatography coupled to mass spectrometry led to the identification of histone H2A.Z as a protein capable of binding ST1926 specifically. The result was confirmed by studies involving Surface Plasmon Resonance (SPR). This indicates that H2A.Z is a primary target of ST1926 and links the perturbations of the histone pathway observed by microarray analysis to the DNA damage and apoptotic responses caused by the atypical retinoid. Comparison of the whole-genome gene-expression profiles of the ST1926-sensitive NB4 and the ST1926-resistant NB4.437r cell lines demonstrated differential expression of numerous genes. Network analysis of the data indicated enrichment of the cellular pathways controlling cAMP (cyclic adenosinemonophosphate)-dependent signal transduction, proteasome-dependent protein degradation and nuclear histones in NB4.437r cells. Pharmacological inhibition of cAMP-dependent protein kinase A with H89 partially reverted resistance of NB4.437r cells to ST1926. Conversely, inhibition of the proteasome with MG132 or bortezomib blocked the apoptotic response afforded by ST1926 in the NB4 cell line. This last effect was associated with a dramatic reduction in the DNA damage caused by the atypical retinoid. The results corroborate the idea that DNA damage is an important determinant of ST1926 apoptotic activity. More importantly, they demonstrate a proactive role of the proteasome in the DNA damaging and ensuing apoptotic response observed upon the challenge of acute myeloid leukaemia cells with ST1926. © 2012 Elsevier Ltd. All rights reserved. Source
Tarragon E.,Jaume I University |
Tarragon E.,University of Murcia |
Lopez D.,University of Murcia |
Estrada C.,University of Murcia |
And 15 more authors.
Neuropharmacology | Year: 2014
Memory loss is one of the key features of cognitive impairment in either aging, Mild Cognitive Impairment (MCI) or dementia. Pharmacological treatments for memory loss are today focused on addressing symptomatology. One of these approved compounds is memantine, a partial NMDA receptor antagonist that has proved its beneficial effects in cognition. The Octodon degus (O. degus) has been recently proposed as a potential model relevant for neurodegenerative diseases. However, there are no previous studies investigating the effect of pharmacological treatments for age-related cognitive impairment in this rodent. In this work we aimed to evaluate the effect of memantine on sleep deprivation (SD)-induced memory impairment in young and old O. degus. Young and old animals were trained in different behavioral paradigms validated for memory evaluation, and randomly assigned to a control (CTL, n = 14) or an SD (n = 14) condition, and treated with vehicle or memantine (10-mg/Kg i.p.) before the SD started. We demonstrate that SD impairs memory in both young and old animals, although the effect in the old group was significantly more severe (P < 0.05). Memantine pretreatment was able to prevent the cognitive impairment caused by SD in both age groups, while it had no negative effect on CTL animals. The positive effect of memantine in counteracting the negative effect of SD on the retrieval process even in the aged O. degus further supports the translational potential of both the challenge and the species, and will enable a better understanding of the behavioral features of memantine effects, especially related with reference and working memories. © 2014 Elsevier Ltd. All rights reserved. Source
Stravalaci M.,Laboratory of Pharmacodynamics and Pharmacokinetics |
Bastone A.,Laboratory of Pharmacodynamics and Pharmacokinetics |
Beeg M.,Laboratory of Pharmacodynamics and Pharmacokinetics |
Cagnotto A.,Laboratory of Pharmacodynamics and Pharmacokinetics |
And 12 more authors.
Journal of Biological Chemistry | Year: 2012
Soluble oligomers of the amyloid-β (Aβ) peptide play a key role in the pathogenesis of Alzheimer's disease, but their elusive nature makes their detection challenging. Here we describe a novel immunoassay based on surface plasmon resonance (SPR) that specifically recognizes biologically active Aβ oligomers. As a capturing agent, we immobilized on the sensor chip the monoclonal antibody 4G8, which targets a central hydrophobic region of Aβ. This SPR assay allows specific recognition of oligomeric intermediates that rapidly appear and disappear during the incubation of synthetic Aβ1-42, discriminating them from monomers and higher order aggregates. The species recognized by SPR generate ionic currents in artificial lipid bilayers and inhibit the physiological pharyngeal contractions in Caenorhabditis elegans, a new method for testing the toxic potential of Aβ oligomers. With these assays we found that the formation of biologically relevant Aβ oligomers is inhibited by epigallocatechin gallate and increased by the A2V mutation, previously reported to induce early onset dementia. The SPR-based immunoassay provides new opportunities for detection of toxic Aβ oligomers in biological samples and could be adapted to study misfolding proteins in other neurodegenerative disorders. © 2012 by The American Society for Biochemistry and Molecular Biology, Inc. Source